HAO 2010 PROFILES IN SCIENCE: Dr. Gang Lu
Contact
303-497-1554
ganglu@ucar.edu
Dr. Gang Lu obtained a B.S. degree in Physics from Zhejiang University in China in 1982, and a Ph.D. degree in Space Physics from Rice University in 1991. She has worked at HAO since 1992, where she was a Postdoctoral visitor from 1992-1993, and a research scientist from 1993 to the present.
Dr. Lu has worked actively on the analysis and interpretation of various ground- and space-based observations, including ground magnetometers, coherent and incoherent scatter radars, satellite electric and magnetic fields and particles, and auroral images. She also has extensive experience in numerical modeling, including the Assimilative Mapping of Ionospheric Electrodynamics (AMIE), the Thermosphere-Ionosphere Electrodynamics General Circulation Model (TIEGCM), and the Thermosphere-Ionosphere-Mesosphere Electrodynamics General Circulation Model (TIMEGCM)
Her primary research interests are in high-latitude ionospheric electrodynamics, solar wind-magnetosphere-ionosphere thermosphere coupling, and space weather. She has authored and co-authored over 90 refereed scientific papers.
Dr. Lu has an extensive community service record. She served as a member of the National Academy of Sciences Committee on Solar and Space Physics, the Geospace Environment Modeling (GEM) Steering Committee, a Scientific Discipline Representative of the Committee on Solar-Terrestrial Physics (SCOSTEP), the Aeronomy Secretary for the Space Physics and Aeronomy Section of American Geopgysical Union (AGU), and an associate editor for Journal of Geophysical Research - Space Physics. She is currently the Scientific Secretary of SCOSTEP.
She has received the following awards: 2001 Editor citation for Excellence in Refereeing for Journal of Geophysics Research - Space Physics, 1988-1989 Zonta Amelia Earhart Award, and 1988 William and Elva Gordon Scholar, Rice University.
Publication:
(1) Investigation of the relationship between Joule heating and nitric oxide radiative cooling in the thermosphere
Lu, G., M. G. Mlynczak, L. A. Hunt, T. N. Woods, and R. G. Roble (2010), J. Geophys. Res., 115, A05306, doi:10.1029/2009JA014662.
During geomagnetic storms Joule heating dissipation is the dominant form of magnetospheric energy input that is responsible for many chemical and dynamical variations in the thermosphere. One such thermospheric variation is the dramatic increase of thermospheric temperature and nitric oxide (NO) density and thus radiative emission by NO. This paper gives for the first time a quantitative assessment of the relationship between global Joule heating power and global NO radiative cooling power. It is found that, when averaged over a time interval of 24 h along with a time lag of 10 h, global Joule heating power is closely correlated with global NO cooling power. On average, the increased energy release through NO 5.3µm infrared emission accounts for about 80% of Joule heating energy input under disturbed conditions. The paper also presents a first attempt to parameterize global NO power using the Kp and F10.7 indices. Under nonstorm conditions the best correlation is found when the daily global NO power lags behind the solar flux input by 1 day. The predicted NO power based on this parameterization scheme reproduces many features in the observed global NO power by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument over the 7 year period from 2002 to 2008. The predicted global NO power correlates well with the SABER measurements, with a correlation coefficient of 0.89.
Publication:
(2) Observations and Interpretation of a High-latitude Stable Electron Auroral Emission
C. Cattell, J. Dombeck, A. Preiwisch, S. Thaller, P. Vo, L.B. Wilson III, J. Wygant, S. B. Mende, H. U. Frey, R. Ilie, and G. Lu (2010), submitted to J. Geophys. Res.
A collaborative study was carried out led by Cindy Cattell at University of Minnesota to investigate an intense auroral emission as observed on August 17, 2001 by the IMAGE satellite at ~16 MLT, poleward of the main auroral oval. The event lasted for approximately 45 minutes, from before the onset of a large substorm (AE~1400 nT) through the recovery phase. Strong field-aligned currents and Poynting flux were observed by the Polar satellite as it transited field-lines mapping to the auroral spot. Both the Polar particle signature and MHD simulations identify the region as the cusp. This event occurred during an interval when the IMF was large, and duskward and southward. Although the observed emission had some characteristics similar to the electron emission ‘HiLDA’ (High-latitude dayside aurora) and to the ‘proton spot’ observed at the foot of reconnecting field lines, there are distinct differences. The data presented herein are consistent with the hypothesis that the long lasting electron auroral spot maps to the magnetopause region where reconnection was occurring. Under the assumption of conjugacy between northern and southern hemisphere on these field lines, the Polar data suggest that the electrons on these field lines were accelerated by Alfven waves and/or a quasi-static electric field, primarily at altitudes below a few Re since the in-situ Poynting flux (mapped to 100 km) is comparable to the energy flux of the emission while the mapped in-situ electron energy flux is much smaller. The observations are consistent with the interpretation that this event provides the first example of an emission due to electrons accelerated at low altitudes at the foot point of a region of quasi-steady dayside reconnection. Cluster data in the magnetotail indicate that the Poynting flux from the region of magnetotail reconnection is large enough to account for the observed nightside aurora during this event.